Married couples are not saints, and sin is not some error which we may renounce one of these days in order to adopt a more accurate truth. We are unendingly and incessantly in the thick of the struggle between nature and grace; unendingly and incessantly unhappy and then happy. But the horizon has not remained the same. A fidelity maintained in the Name of what does not change as we change will gradually disclose some of its mystery: beyond tragedy another happiness waits. A happiness resembling the old, but no longer belonging to the form of the world, for this new happiness transforms the world.
--Denis de Rougemont, Love in the Western World